Two years after 9/11, the U.S. government tried to flip members of al-Qaeda held in Guantanamo and turn them into agents for the Central Intelligence Agency (CIA), according to the Associated Press (AP).

The CIA operated the secret program from 2003 to 2006 in a special wing of Guantanamo named “Penny Lane.”

The facility was also known as “The Marriott” due to its luxurious accommodations—participants lived in cottages equipped with plush beds, private kitchens, patios, showers and televisions. Willing detainees were also provided with money and pornography as long as they agreed to serve as CIA spies once released from the prison.

Of the 779 people held at Guantanamo, only a few dozen were ever considered for Penny Lane, and only a fraction of those went on to work for the CIA.

Millions of dollars were spent on the program, but it is not known if any of the double agents sent back to their home countries on assignment ever delivered actionable information to the CIA. However, it was learned that some of those former detainees stopped sending information to the agency altogether and finally disappeared.

President George W. Bush, under whose administration the program was developed, personally interviewed CIA officers participating in the operation. All the while, officials in his administration expressed grave concerns over potential problems that could arise.

These included the risks that “turned” detainees would rejoin al-Qaeda after being freed, or that they would pass on false information to cause inaccurate drone strikes on civilians in al-Qaeda strongholds in Afghanistan and Yemen.

There was also the risk that a double agent would take part in a terrorist act and then publicize the fact that he had been on the CIA payroll.

“When I juxtapose that to the CIA actually thinking that they can convert these people, I think it was very ill-conceived program for them to think that,” Senator Kelly Ayotte (R-New Hampshire) said on MSNBC. “These are some very hard-core individuals and many whom have been released by both administrations have gotten back in to fight us and our allies, unfortunately.”

Senator Bob Casey (D-Pennsylvania), interviewed on the same network, agreed. “It has a degree of recklessness to it that I would be very concerned about,” he said.

AP learned of the program from interviews it conducted with about a dozen current and former U.S. officials.